1. Field of the Invention.
The present invention relates generally to electrical equipment that is assembled to satisfy individual customer orders, and more particularly to switchboards.
2. Description of the Related Art.
A switchboard is a kind of electrical power distribution unit. Electrical power to a building flows from high voltage utility lines to step-down transformers, from the transformers to one or more switchboards, and from the switchboards to branch or distribution circuits for lighting, heating and air conditioning, elevators, pumps, and electrical outlets. The switchboards include utility metering devices, mains protection devices, and branch or distribution protection devices. Each switchboard may have only utility metering devices, only mains protection devices or only branch or distribution protection devices, or various combinations of these devices. Each switchboard includes a metal box typically mounted as a free standing unit on the floor of a utility room in the building. A switchboard typically has a current rating of 600 to 4000 amperes. A very large building or installation such as an airport will typically have a number of switchboards.
Traditionally, a customer through a sales person provided specifications for a switchboard to an order engineer. The order engineer custom designed the entire switchboard using a software tool. There are millions of possible switchboard configurations, about 3,000 of which were designed annually. About 30% of the time, the order engineer would use an existing standard switchboard configuration. The other 70% of the time, the order engineer would custom engineer a new configuration. Custom designs were almost never re-used. The components were then fabricated, purchased, or taken from inventory, and then assembled according the desired switchboard configuration.
The software tool used by the order engineer was a kind of order entry computer system. An example of such an order entry system is described in Geier et al., U.S. Pat. No. 4,984,155 entitled "Order Entry System Having Catalog Assistance," incorporated herein by reference, and Phillips et al., U.S. Pat. No. 5,047,959 entitled "Flexible Data Display," incorporated herein by reference. Once the order engineer chose the components to be custom assembled into a switchboard, the software tool generated a bill of materials to be used by a materials management (MRP) computer system. The software tool was automatically linked to the MRP system. The MRP system managed inventory, ordered parts, and managed production capacity. The MRP system ensured that all of the components needed for assembling the switchboard were available at or delivered to an assembly location by the time when the switchboard would be scheduled for assembly.
The switchboard market is rather mature. It is a very competitive market. The complexity of the product has traditionally had a strong impact on the profitability of the switchboard business. Computer-based tools and modern management techniques, such as flexible manufacturing, just-in-time inventory, component count and cost reduction programs, and a total customer satisfaction objective, have been applied over the years with some success to deliver a quality product at a reasonable price. Small players have survived in the market due to their flexibility, short lead-times, low labor costs, and close customer relationships.